What happens when the nest was built in a flower pot on 2nd floor balcony, and below is cement?

the morning doves eggs hatched 2 days ago. what happens when its time for them to leave the nest, they're on the 2nd floor in a flower pot attached to the railing. My concern is, there is nothing but concrete below. what will happen, when the time comes and she pushes them out of the nest, and they don't know how to fly yet? Concerned, Regina Bailey